Rotary stencil printer having clamping means and guiding means



Oct. 28, 1947. D. DOOLITTLE v 2,429,927 ROTARY STENCIL PRIN'ER HAVING CLAMFING MEANS AND GUIDING MEANS Filed Oct. 16, 1945 2 Sheets-Sheet 1 'lill/111111111111111 m INVENTOR. aws oaz /rrzf Oct. 28, 1947. D. DooLlTTLE l 2,429,927

ROTARY STENCIvL PRINTER HAVING (IL AMING MEANS AND GUIDINGMEANS Filed Oct.A 16, 1945 2 Sheets-Sheet` 2 INVENToR. 0,944? @az/7725 BY fg@ mmm/awww# Patented Oct. 28, 1947 UNITED STATES PATENT OFFICE ROTARY STENCIL PRINTER HAVING CLAMPING MEANS AND GUIDING MEANS yDuane Doolittle, Lincolnville, Maine Application October 16, 1945, Serial No. 622,533

minimizes the expense attendant upon such proiied in the construction hereinafter set forth and duction.

A more specic object of the invention is to provide such apparatus which in the making of mimeograph copies effectively utilizes a stencilcarrying cylinder which is rolled over a sheet of paper to be printed as it rests upon a relatively fixed base surface and which assures, in manual forward rolling of the cylinder during a printing, a setting up of certain conditions which will automatically and efficiently return the parts to their initial positions when the device is bodily lifted from the base surface and returned to its starting position for a repeat printing.

Another object of the' invention is to provide a relatively stiff but flexible sheet having a smooth hard surface which may serve as an eilisembly of parts effectively anchors in position the inking cloth and structural embodiments thereof which are readily constructed and allow efficient use and operation.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, which will be exemplithe scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the` invention, reference should be had to the following detailed description taken in coninvention, showing a protective cover in position;

Fig. 2 is a sectional view of the apparatus -shown in Fig. 1, taken on line 2-2 thereof;

Fig. 3 is a sectional view similar to Fig. 2, but with the protective cover omitted for printing use of the apparatus, with parts broken away,

cient cover for the stencil-carrying cylinder since it is of a protective character, which permits eilicient employment in wrapping a cut stencil about the cylinder and constant observation of the stencil during such operation to assure proper placement of the stencil, and which may be used to economical advantage as a backing means for stencil sheet material during cutting of the latter thereby eliminating necessity for made up stencil assemblies each comprising a backing sheet that is torn off from the stencil sheet mount and thrown away subsequent to cutting, a common practice prior to the present invention.

A further object of the present invention is to provide such mimeograph apparatus which will permit eicient production` of mimeographed copies with the printing accurately placed or positioned as desired on the successively printed copies even though they are produced'by rolling a stencil-carrying cylinder manually over a base surface on which the printing paper is placed, the apparatus being characterized by guide means mounted thereon in a simple manner, which may be easily aligned with a reference mark on the base surface, and with means assuring that the other parts of the apparatus have assumed their initial positions as the printing cylinder is manually placed in starting position,

Still another object of the present invention is to provide such apparatus in which simple asshowing only the portion of the printing cylinder adjacent the clamping plate and associated parts, together with guide means provided for assurance of eicient printing;

Fig. 4 is a front view, looking into the angle of the bent guide means of sheet material shown inV mounted position in Fig. 3;

Fig. 5 is an enlarged detailed sectional view of the apparatus shown in Fig. 1, indicating the construction at the ends of the printing cylinder;

,fmodied form of the apparatus of the present invention, but omitting the guide means.

In the drawings like numerals identify like parts throughout. The embodiment of the apparatus shown in Figs. 1 to 5 inclusive comprises a printing cylinder l0 preferably formed of perforated sheet metal or other relatively rigid material bent into cylindrical form. About the perl forated sheet metal printing cylinder or drum I0 is wrapped an inking cloth Il which is initially wider than the cylinder to provide marginal edges I2, I2 with each turned inward about the adjacent end edge of the cylinder and into the latter. A pair of end members I3, I3 are provided each of which may comprise a disc having a circular portion or shoulder Ill to be received snugly within the end of the cylinder I and tightly to clamp therebetween the inwardly turned marginal portion I2 of the inking cloth I I. If desired, each end member or disc I3 may be of greater diameter than the inner diameter of the cylinder IIJ and provided with the circular shoulder I-i by rabbeting so as to form an end flange I5 which will seat against the end of the cylinder with inking cloth interposed when the end member or disc is driven home to clamp the parts together. sary provision of additional fastening means to secure the parts together, thereby assuring simplicity and economy of construction while providing for secure anchorage of the inking cloth in a desired stretched condition.

Further anchorage of the inking cloth il may be attained if desired by gluing the ends thereof to the cylinder III as it is Wrapped around the latter, in a certain zone which, as indicated in Fig. 2, may extend an appreciable distance peripherally of the cylinder Ill, say from a point It to a point Il, and completely across the cylinder in an axial direction.

The printing cylinder may be imperforate for some uses, in which case ink would be supplied to the inking cloth II from the outside. Preferably, however, the inking cylinder Ill is K'perforate and ink supplied to the inking cloth II from the interior of the cylinder. To assure even distribution of ink on the inner wall of the cylinder so that the inking cloth I I will be supplied with ink from the interior of the cylinder through the perforations thereof throughout the effective surface of the inking cloth, a permeable layer of felt I8 is laid up against the inner wall of the cylinder and may be held or anchored in position in any suitable manner. Such anchorage of felt layer It may be accomplished in many ways as by having its end edges at I3, I9 abutting the inner faces of the end members or discs I3, I3. Split rings may he snapped into position interiorly of the felt layer to press it radially outward against the inner wall of cylinder Ic. The ends of the layer of felt I8 alternatively may be anchored by an interior clamping plate 2E! in the'zone IIS-Il. In the latter zone an ink access hole 2 i, or a plurality thereof, if desired, is provided through the perforated cylinder III and any underlying structure, such as the layer of felt I3 and clamping plate 2li. Such ink access hole or holes 2l, of course, will also extend through the inking cloth I I if a portion thereof extends to and beyond the location of such inkinlg hole or holes. Introduction of a quantity of ink through the inking hole or holes 2l to the interior of the printing cylinder Iii will result in a thorough wetting of the felt layer IB when the cylinder is oscillated or rotated. The ink saturating the felt layer I3 will then be fed through the perforations in the cylinder Ill to the inking cloth II, the thickness of the perforated sheet metal of the cylinder and the character of the cloth and felt preferably beingV such as to assure physical contact through the perforations of the metal cylinder between portions vof the inking cloth and the felt layer.

As a result, efficient feed of ink from the interiorf Such structural features make unneces- For the purpose of clamping a cut stencil in position wrapped around the cylinder Il), an arcuate clamping plate 22 is provided which preferably covers the zone I6-I'I of the printing cylinder. Releasable fastening means are provided for removably anchoring the clamping plate 22 to the cylinder III. Such means may comprise a stud or bolt 23 extending through the cylinder wall in the zone IG-I'I and anchored to the cylinder in any suitable manner, such as by being threaded into an internally :threaded hole through the cylinder Wall. The stud or bolt 23 may have a head 24 interiorly of the cylinder I between which and the inner wall of the cylinder I6 portions of the felt layer I8 and the interior plate 2B may be clamped, as proposed in Figs. 1 and 2; or, if desired, with omission of the interior Plate, the head of the bolt may clamp portions of the felt layer against the inner wall ofthe cylinder, as suggested in Fig. 3. As indicated in Figs. l, i2 and 3, the stud or bolt 23 extends outwardly from .the cylinder I0 through a hole in the arcuate clamping plate 22 and threadably receives therebeyond a cap nu-t 25 adapted, when screwed down upon the stud, to clamp the parts together and, when removed, to permit removal of the clamping plate for mounting a cut stencil and guide, and/or a protective cover about the cylinder.

As shown in-Figs. 1 and 2, the end members or discs I3, I3 are each'provided with an axial hole through which is received a shaft 25 with the ends thereof 2l, 21 extending beyond the end members or discs. Each end 21 of the shaft 23 is externally threaded and a manual knob or hand grasp 28 is screwed thereon. Each manual knob 23 is provided with a necked portion 23 which, when the apparatus is not in use, may rest in a notch or fork 30 on the end of an arm 3I supported upon a base 32 of a supporting stand.

The shaft 25 on the inside of the cylinder IIB has fixed thereto at 33 suitable spring means 3l! tied or anchored to the cylinder II! at 35. As shown in Figs. land 2, such spring means 313 may comprise a helical spring disposed about the shaft 26 having one end received in a hole in the shaft at 33 and the other end 36 `extending radially outwardly through one of the perforations in the cylinder I0, then laterally and back through another perforation in the cylinder, as shown at 35.

ZAs a result of such tying of ythe shaft 26 and the cylinder III. together by spring means, when the cylinder is placed upon a base surface the manual knobs 28, 23 rlrmly grasped and the shaft 26 bodily transported "forward without rotation, the spring 34 will b-e wound up about the shaft 26 as the cylinder rolls over the base surface. Thus when the apparatus Vis then lifted from contact with the base surface, the spring 34-will unwind, rotating the printing cylinder I0 in the reverse direction to its initial position so that the apparatus may then be returned to its starting position on the base surface with the parts in their relative initial positions.

It will be -understood that, to use the device in the making of mimeographed copies, a cut sheet of stencil paper is to be wrapped around the cylinder Ill Voverlying the inking cloth I I, and that the stencil will vbe held securely in position by 4having its ends clamped beneath the clamping between the paper and the stencil being attained by movement of the cylinder supporting the stencil relative to the paper, which is held stationary, rather than by reverse operation of rotating the cylinder about a fixed axis and permitting the paper to move beneath it, as is common practice. Such procedure, however, will not assure proper orientation or placement of printing on the paper relative to the marginsthereof.

Such proper orientation is assured in accordance with the present invention by the employlment of suitable guide means. This guide means,

as shown in Figs. 3 and 4 may comprise a piece of sheet material 31 which may be formed of relatively stiff cardboard or sheet plastic having one end portion 38 defined from another end portion 39 by a transversely extending bend or fold line 40, and With the twoportions disposed relative to each other to form an acute angle therebetween. As shown in Fig. 3, after a cut stencil sheet 4| has been wrapped around the cylinder ID with the inking cloth |l lying therebeneath (and, of course, with the cap nut 25 and clamping plate 22 loosened or removed) the guide 37 will be plaed with its portion 38 overlying the head end of the stencil 4| at 42. The clamping plate 22 will then be laid over the portion 38 of the guide 3l and the cap nut 25 screwed down to clamp the parts together. As a result, the portion 39 of the guide 31 will extend obliquely away from the cylinder I6 toward the fastening means or stud 23 and cap nut 25 assembly, as shown in Fig. 3. Although the guide 3'! is preferably shaped as shown in Fig. 3 its portion 39 may be disposed with respect to portion 38 at other angles so long as it will readily flex, or bend` along fold line 46, as to assume proper position when the apparatus is placed in its initial or starting position at time of use.

Since it is desired to employ the stud 23 and lcap nut 25 or fastening means assembly as a guide for proper angular positioning of the apparatus relative to the base surface, such as by contact of the nearer portion at 43 of the cap nut with the base surface as the cylinder and stencil assembly are brought down to rest upon the base surface in starting position, the guide 31 has its portion 36 so shaped or constructed as to permit this action while assuring projection of the terminal edge 44 of the portion 39 beyond the fastening means as desired. For this purpose portion 39 of the guide 3l may be suitably cut away or apertured, and is preferably provided with a notch 45 in its terminal edge 44. Such notchor aperture will also provide ready access to the nut 25 rfor loosening, removing or tightening the same.

The apparatus desirably includes a protective cover 46 of suitable sheet material so as to avoid ink smears or smudges o-n objects accidentally brought into contact with the apparatus Ywhen not in use with or without the presence of a cut stencil. This protective cover 46 may be provided in a form which will permit its eilicient employment in certain procedural steps preparing the apparatus for producing mimeographed copies and/0r in the production of the latter. Such protective covering 46 may be a relatively stiif but flexible sheet of suitable material such as transparent, translucent or opaque plastic. It preferably comprises a transparent sheet of suitable material, such as a flexible sheet of transparent plastic having a fair degree of stiffness and a relatively smooth hard surface. The useful protective characteristic of the covering sheet 46 is illustrated in Figs. l and 2, wherein it is indicated that the transparent plastic sheet is Wrapped about the cylinder I6 and its overlying elements, such as the inking cloth and a cut stencil 4|. The ends of the protective sheet 46 are clamped in position beneath clamping plate 22. This protective cover 46 also enhances the appearance of the idle apparatus.

Another useful feature of the protective sheet 46 is illustrated in Fig. 7, wherein it is indicated that the cut stencil sheet 4| may be eiciently applied to the exterior of the printing cylinder I6 with the aid of the transparent sheet 46. This procedure is accomplished in the following manner: The cap nut 25 and clamping plate 22 are removed. Precaution is taken to assure a sufcient quantity of ink within the printing cylinder. A out stencil sheet 4| is then positioned with its end edge at the head properly located in the zone |6|1.

For this purpose the device may be provided with ar suitable guide mark with which the end edge at the head of the cut stencil 4| may be aligned. Such guide mark may be provided by an end edge of the inking cloth or by a suitable mark on the end portion thereof or upon any overlying element.

The flexible transparent, relatively stift sheet 46 is then employed to wrap the cut stencil 4| about the cylinder i6. This may be accomplished either by having the cut stencil lying against the undersurface of the transparent sheet 46 at the time the cut stencil has its end edge at the head aligned with the index mark on the cylinder, or the transparent sheet 46 may be brought down upon the stencil sheet 4| after the latter has had its head end properly placedron the cylinder. The two sheets comprising the stencil 4| and the transparent sheet 46 are then wrapped about the cylinder I0, The transparency of sheet 46 permits continua] observation of' the underlying stencil sheet 4| during the wrapping of the latter about the cylinder so that one can make certain that the stencil is properly stretched and smoothed about cylinder ||l and that the ink starts evenly through the cut places in the stencil.

After so wrapping the out stencill 4| about the cylinder lll, the ink in the inking cloth will assure that it will be held in its smoothed condition while the transparent sheet 46 is being replaced by the guide 31 and clamping plate 22, and the cap nut 25 is being screwed down securely. Of course, this procedure will smear the undersurface of the transparent sheet with ink. These smears can, however, readily be removed by wiping or other simple cleansing action, due to the nature of the material from which the transparent sheet is made.

This simplified procedure in mounting the stencil sheet 4| eliminates the necessity for having the stencil sheet fastened to a heading strip provided with eyelets adapted to be engaged over hooks or studs, as is common practice. Further, it permits the employment of unbacked stencil sheets precut and stacked or cut from a roll of stencil sheet material at time of use, as contrasted with the usual practice of using stencil sheets which, in addition to having an apertured heading strip, are provided with a tear-off relatively stiif paper backing sheet. This economy inmaterials and procedure, of course, however, will require the provision of some sort of backing sheet to be used inthe cutting of the stencils. As

lindicated below, this necessity may be answered by the transparent sheet 46, which, as previously -ginal edges `of the .piece -of paper.

pointed out, will also serve both as a'protective cover and as an aid in the wrapping of a cut stencil 4| into position on the cylinder i8 in the following manner.

The transparent flexible, relatively stiff sheet 4S may also serve as a backing sheet in the cutting of stencils. A piece of stencil paper 4I may be cut from a roll thereof. This may then be placed upon the transparent sheet 46, The two together may then be rolled into a typewriter and the stencil sheet 4l cut with the desired `message while using the transparent sheet 46 next to the platen as a protective backing sheet. Upon removal of the cut stencil 4l with the transparent sheet 46 from the typewriter, the two may be vof the transparent sheet 4S permits it to lie flat for this purpose when it is not being bent around in the wrapping of a cut stencil about the cylinder or wrapped around the latter as a'protective g cover therefor.

It will thus be seen that the protective sheet 46 `should have certain characteristics. It should be transparent to permit observation therethrough. It should be relatively stiff so that it will lie flat when unflexed. It should be of such character as to have `a smooth, hard surface and be relatively impervious to liquids so as to provide an ideal backing for the cutting of stencils and to provide for ready removal of ink smears therefrom. And further, it should be flexible to permit its employment as an aid in the wrapping of a cut stencil about the cylinder or as a protective cover for the printing cylinder. A relatively thick sheet of transparent plastic, such as cellulose acetate, Cellophane or other well known plastic sheet materials, will satisfy these requirements.

In operation of the apparatus aprimary base surface, such as Va table top with an overlying cover or sheet on which marks may be made, as diagrammatically indicated Aat 4l in Fig. 6, is selected. The operator will place thereon reference marks, such as those indicated at 4B, 48, to which are to be aligned the terminal edge 44 of portion 88 of the guide Sl. The duplicating 'apparatus is set up with a cut stencil lili wrapped Aabout the cylinder i8 and the guide 3l clamped in proper position, ail in the manner as proposed above. The apparatus is then bodily moved to the base surface il with the hands of the operator grasping the manual knobs 28, 28,*and the cylinder is placed upon the base surface with the terminal edge 44 of the guide 3l aligned with the marks 58, and also with the portion 48 of the clamping cap nut 2e resting upon the base surface. The operator then transports the `shaft 26 'and its knobs 28, 28 forward without rotation to cause the printing cylinder lll to roll across the base surface fil. This will cause a printing of the indicia cut -in the stencil down upon the base surface 4l.

The `operator then places or arranges` a blank `sheet of paper 4% upon `the base surface 4l in a manner so that ythe printing will be arranged or oriented as Ydesired 'with respect to the mar- The `operator places reference marks upon the base surface 41,

-suchlas .those at 59, et, to guide nimin proper placement of the succeeding sheets of paper to be printed.

The duplicating apparatus -isthen positioned as described above, with the terminal edge 44 of guide 3l aligned'with the marks 48, 4-8, and with fthe cap nut 25 resting against the base surface 4l at 43. Thereafter, the operator rolls the printing cylinder forward in the manner indicated above so that the sheet of paper 4S will be printed in the desired manner with the printing properly oriented thereon. The operator then bodily picks up the duplicating apparatus, substitutes van unprinted sheet for vthe printed sheet at 49 with its corners aligned with the marks "58, 5i] and then repeats the `operation for printing of the next succeeding Asheets to be mimeographed.

It will thus be seen that the guide lines or marks 513, 50 properly dictate placement o'f the vsheets of paper -49 so that the printing will be properly orientedthereon, that the guide lines or index marks e8, 48 will properly dictate placement of the printing cylinder sothat the printing on the sheet will begin'at'the head end where desired, and that contact of the fastening-means or the cap nut 25 with the base surface 41 at 4?, will assure, in cooperation with the guide 3l when its edge 44 is aligned ywith the marks 48, 48, the proper placement at the starting position of the apparatus relative to the paper to be printed. As indicated above, the return spring 34 assures that the printing cylinder will be rotated in a reverse direction after having been rolled forward duringprinting so as to permit the guide 3l andfastening means or cap nut 25 to be located in theirinitial positions.

As'shown in Fig. 8, an embodiment of the invention may comprise a perforated cylinder I0 around which is wrapped Vthe inking vcloth il which may be secured thereto in the manner indicated above, such as by having inwardly turned edges thereof clamped between the inner wall of the cylinder and the end members I3, i3. VThe ends of the inking cloth Il may be employed to render'imperforate or close the apertures in the zone l-ll of the perforated cylinder l0. This may be accomplished by gluing those ends to the cylinder lil in that zone. In A,such case the ink access hole 2l 'will lbe formed through a portion of the inking cloth. The latter may be further anchored in position by an Vinner plate 5l which may khave a Athreaded hole therein into which the stud 2S is screwed so as tightly to clamp the ends of the inking cloth ll to the outer surface ofthe cylinderfl. In the case of the employment lof 'the 'inner :clamping .plate 5l a hole 52 will be formed therein aligned with the ink access hole 24. YSuch inner clamping plate 5I may supplement the gluing to render the zone IG--l'i imperforate except for the ink access hole 2l, or it may be employed in substitution for the gluing.

The ink access. hole may vbe closed by lapping over itY the end 53 of the cut stencil 4i and holding the latter tightly down against the inner plate E! by meansof the clamping plate .22. This will prevent spilling out of any excess ink in the printing cylinder.

As indicated above, any suitable reference means in the zone IS-l'l of the printing cylinder may be employed for dictating the proper location of the edge of the stencil sheet el at its head end when being wrapped around and mounted on the printing cylinder lll. For thispurpose, in the `embodiment shown in Fig. 8 the inner plate V5l may be provided at 54 with a suitable scratch or mark at which the head end of the cut stencil 4I is to be positioned. Of course, it will be understood that with reference to the embodiment shown in Fig. 8 it is intended that a suitable guide means, such as that shown at 31 in Figs. 3 and 4, may be employed to advantage and in a similar manner. As proposed in Fig. 8, the apparatus may, if desired, be employed without the use of the inner layer of felt I8. It will be understood, however, that if desired such an ink spreading felt layer I8 may be employed within the cylinder I of the embodiment shown in Fig. 8.

It will thus be seen that the objects set forth above and those made apparent from the above description are efliciently attained, and since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings Shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A duplicating apparatus comprising, in combination, a printing cylinder of sheet material, an inking cloth wrapped therearound and anchored thereto in the vicinity of a certain zone With the cloth being initially wider than said cylinder, a pair of end members each having a circular portion received snugly within an end of said cylinder with an edge of said inking cloth turned inward about the end edge of said cylinder into the latter and clamped tightly between said circular portion of said end member and the inner surface of said cylinder, a shaft rotatably received through said end members and carrying beyond the latter means to permit manual transport thereof without rotation, spring means tying said cylinder to said shaft to be wound up as said cylinder is rolled forward over a base surface by said shaft without rotation of the latter for return of the cylinder to its angular starting position when the device is lifted bodily from the base surface, a clamping plate overlying that zone adapted to clamp a stencil sheet in position about said cylinder, and

printing guide means comprising a bent piece of sheet material having one end portion clamped beneath said clampingplate and the other end portion extending away from said cylinder and terminating in an edge adapted to be aligned with reference means on the base4 surface forproper location of printing on paper prearranged on the base surface with respect to the reference means.

2. A duplicating apparatus comprising, in combination, a printing cylinder of sheet material, an inking cloth wrapped therearound and anchored vthereto in the vicinity of a certain zone with the cloth being initially wider than said cylinder, a pair of end members each having a circular portion received snugly within an end of said cylinder with an edge of said inking cloth turned inward about the end edge of said cylinder into the latter and clamped tightly between said circular portion of said end member and the inner surface of said cylinder, a shaft rotatably received through said end members and carrying beyond the latter means to permit manual transport thereof without rotation, spring means tying said cylinder to said shaft to be wound up as said cylinder is rolled forward over a base surface by said shaft without rotation of the latter for return of the cylinder to its angular starting position when the device is lifted bodily from the base surface, a clamping plate overlying that zone adapted to clamp a stencil sheet in position about said cylinder, and printing guide means comprising a bent piece of sheet material having one end portion clamped beneath said clamping plate and the other end portion extending back over a portion of said clamping plate to extend obliquely away from said cylinder and terminating in an edge adapted to be aligned with reference means on the base surface for proper location of printing on paper prearranged on the base surface with respect to the reference means.

3. A duplicating apparatus comprising, incombination, a printing cylinder of perforate sheet material, an inking cloth wrapped therearound and anchored thereto in the vicinity of a certain Zone with the cloth being initially wider than said cylinder, a pair of end members each having a circular portion received snugly within an end of said cylinder with an edge of said inking cloth turned inward about the end edge of said cylinder into the latter and clamped tightly between said circular portion of said end member and the inner surface of said cylinder, a shaft rotatably received through said end members and carrying beyond the latter means to permit manual transport thereof without rotation, spring means tying said cylinder to said shaft to be wound up as said cylinder is rolled forward over a base surface by said shaft without rotation of the latter for return of the cylinder to its angular starting'position when the device is lifted bodily from the base surface, the resultant cylindrical structure having in the mentioned zone an ink accesshole extending therethrough to the interior of said cylinder, a clamping plate overlying that zone adapted to clamp a stencil sheet in position about said cylinder and to cover the ink access hole, Areleasable means in said zone projecting beyond said clamping plate and biasing the latter toward said cylinder, and printing guide means comprising a bent piece of sheet material having one end portion clamped beneath said clamping plate and the other end poi'- tion extending back over a portion of said clamping plate to extend obliquely away from said cylinder with portions of its terminal edge extending beyond said releasable means.

4. A duplicating apparatus comprising, in combination, a printing cylinder of perforate sheet material, an inking cloth wrapped therearound and anchored thereto in the vicinity of a certain Zone with the cloth being initially wider than said cylinder, a pair of end members each having a circular portion received snugly within an end of said cylinder with an edge of said inking cloth turned inward about the end edge of said cylinder into the latter and clamped tightly between said circular portion of said end member and the inner surface of said cylinder, a shaft rotatably received through said end members and carrying beyond the latter means to permit manual transport thereof without rotation, spring means tying said cylinder to said shaft to be wound up as said cylinder is rolled forward over a base surface by said shaft without rotation of the latter for return of the cylinder to its angular starting position when the device is lifted bodily from the base surface, the resultant cylindrical structure having in the mentioned zone an ink access hole extending therethroughto the. interior of said cylinder, a clamping plate overlying that zone adapted to. clamp a stencil sheet in position about said cylinder and tofcover the: ink accessv hole, releasable means in said Zone biasing said clamping plate toward said cylinder andprojecting beyond said plate to serve as a limiting-guide for rotational movement of said cylinder over the base surface, and printing guide means comprising abent piece of sheet rnaterial'having one end portion clamped beneath said clamping plate and the other end portion extending back over a portion of said clamping plate to extend obliquely away from said cylinder with portions. of its terminal edge extending beyond said releasable means, said obliquely extending portion of` said guide means being so shaped as to permit said projecting releasable means to contact-,the base surface when the cylinder is placed for printing a sheet of paper on. the ybase. surface with the terminal edge of` said guide means aligned with referenceK means on the basev surfaceA 5. In a` duplicating apparatus, thecombina-tion comprising, a-printingcylinder adapted to carry astencil sheet wrapped therearound. and successively to .print sheets of-` paper on a. base, sur.- ace when said cylinder is rolled thereover, arcleasable clamping plate extending across said cylinder to holdthe ends of the` stencil sheet in position, and printing guide means comprising a piece of sheet materialha-ving one end. portion clamped beneath saidV clampingA plate and the other end. portion extending. away from said. cylinder andterminatingin an edge adapted to be aligned..withreference-means on the base. surface for proper locationv ofy printingon paper` prearranged on the base surface with respect tothe reference means.

6. In al duplicating apparatus, the combination comprising, aA printing cylinder adapted to. carry astencil sheet wrapped therearound and successively to print sheets of paper onY a base surface when. said cylinder is rolled thereover, a releasable clamping plate extending across said cylinder toY hold the-ends of the stencil sheet in position, and printing` guide means comprising a bentA piece-of sheet. material having one end portion clamped beneathfsaid clamping plate and the other end-portion extending back. over. a .portion of said clamping plate toextend` obliquely away from. said. cylinder and terminating in. an edge adapted to-be` aligned with reference means on the base surface. for proper location of printing on paper prearranged on. the base surface with respect to the reference means.

7.. In a duplicating apparatus, the combination comprising, a printing cylinder adapted to carry astencil sheet Wrapped therearound and successively to 4print sheets of paper on a base surface when said cylinder is rolled thereover, areleasable clamping plate extending across said cylinder to` hold theends. of. the stencil sheet in position, releasablemeans projecting beyond said clamping plate and biasing the'latter toward said cylinder, and printing guidemeans comprisinga bent. piece of sheetmaterial having. onev end portion clamped beneath said clamping.V plate and the other end portion extending back over a portion of said clamping plate toextend obliquely away from said cylinder withY portions of its `terminal edge extending beyond said releasable means. f

8. In a duplicating apparatus, the combination comprising, a printing cylinder adapted to carry a stencil sheet wrapped therearound and successively toprint sheets of paper on a base surface When said cylinder is rolled thereover, a releasable clamping. plate extending across saidcylinder tov hold. the ends of thestencil-sheet inposition, releasable means lbiasing said clamping plate toward said cylinder and projecting. beyond said plate. tofserve as a. limiting guide for rotational movementof saidcylinder over the basesurface, and printing guide means comprising a bent piece of sheet material having one end portionclamped beneath said clamping plate and the other end portion extending back over a portion of said clamping plate. to extend obliquely away from said cylinder. Withportions of its terminal edge extending beyond. said releasable means, said obliquely extending portion of said guide means being. so shaped asto permit. said projecting releasable means ltocontact thebasesurface when the cylinder is placed for printing a sheet of paper on the-base. surface with the terminal edge of said guide means alignedwith reference means on the base lsurface.

9.l In a duplicating apparatus, the combination comprising, a .printing cylinder. adapted to carry a stencil sheet wrapped. therearound and successively to. print sheets of paper on a base surface when said cylinder is rolled. thereover, a releasable.y clamping plate extending across said cylinder to-hold the ends of the stencil sheet in position, a threaded stud anchored to said cylinder and. extending up. through a hole in said clamping plate, a nut threaded on said stud and I extending beyond said clamping plate While biasing thev latter toward said cylinder, and a printing guide consisting of a-bent pieceof sheet material having one end portion clamped beneath an edge of said. clamping. plate. and the other end portion-y extendingY Iback over a. portion of said plate. and. obliquely away from said cylinder and beyond said studv and nut assembly, the terminal edge of` said obliquely extending portion being notched to permit said stud and nut assembly to contact. the basev surface when the cylinder is placed for. printing a sheet of paper on the base surface. with the terminal edge aligned with lreference means on the base surface.

DUANE DOOIiITTLE.

REFERENCES CITED The following references are of record in the le of this patent:l

UNITED STATES PATENTS Number Name Date 2,292,602 Biondi Aug.. 11,. 1942 1,643,028l Morlan Sept. 30, 1927 798,800: Klaber Sept. 5, 1905 1,646,576 Castan Oct. 25, 1927 2,236,233 Erickson Mar. 25, 1941 1,829,579 Beach Oct. 27;.1'931 

